London: British scientists have discovered a ‘rogue gene’ which they claim is responsible for long-term back pain, a key breakthrough that may soon pave the way for new and effective treatment for the condition.

A team at Cambridge University has identified the gene, called HCN2, which it says will open up the possibility of new drugs to block the protein produced by the gene.

For their study, the scientists removed the HCN2 gene from pain-sensitive nerves in mice. By measuring speed that the mice withdrew from different types of painful stimuli, they concluded that deleting the HCN2 gene abolished pain.

However, they found that deleting HCN2 did not affect normal acute pain -- which occurs suddenly, for example when biting one's tongue -- a factor they said was important since this type of pain acts as a useful warning signal to the body.

Chronic pain comes in two main varieties and is an enormous health burden worldwide. Inflammatory pain occurs when a persistent injury, such as a burn, results in very sensitive nerve endings and increased pain.

Neuropathic pain occurs when nerves are damaged, causing ongoing pain. This type of chronic pain is often lifelong, say the scientists.

Lead author Professor Peter McNaughton said: "Individuals suffering from neuropathic pain often have little or no respite because of the lack of effective medications. Our research lays the groundwork for development of new drugs to treat chronic pain by blocking HCN2.”

Many genes play a critical role in pain sensation, but in most cases interfering with them simply abolishes all pain, or even all sensation. What is exciting about the work on the HCN2 gene is that removing it eliminates neuropathic pain without affecting normal acute pain.

"This finding could be very valuable clinically because normal pain sensation is essential for avoiding accidental damage," he said.